The present invention relates to a technique of calculating an environmental load amount of each product produced through a production line.
Conventionally, for the purpose of improving products, a manufacturer calculates an amount of an environmental load of each product. For example, power consumption required for producing a product is calculated.
As a method of obtaining such an amount of an environmental load of each product, there are methods exemplified by the method called Life Cycle Assessment (LCA) in which an amount of an environmental load of a product is evaluated over the whole product life cycle ranging from material production, through product manufacturing, to product disposal, and a method disclosed in Japanese Unexamined Patent Laid-Open No. H08-235245 (hereinafter, simply referred to as the document).
According to LCA, an amount of an environmental load of a production line as a whole is allotted to each product according to a ratio of production volumes or production values, to obtain an amount of an environmental load of each product.
According to the method disclosed in the document, each time when production of any lot among a plurality of lots is finished, the actual production volume of each product produced during the interval between that time and the previous time and the total actual amount of environmental load required for producing each lot in that interval is obtained, and then an amount of an environmental load per one unit of product of each lot produced is calculated on the basis of the obtained values. This operation is repeated to obtain fine values.